Apparatus for treating filament yarn



March 13, 1962 BROMLEY ETAL 3,024,516

APPARATUS FOR TREATING FILAMENT YARN Filed May 18, 1959 3 Sheets-Sheet 1FIG. I.

INVENTORS JAMES E. BROMLEY BY WILLIAM H HILLS ,J m Tar AT ORNIY March13, 1962 J. E. BRQMLEY ETAL 3,024,516

APPARATUS FOR TREATING FILAMENT YARN Filed May 18, 1959 3 Sheets-Sheet 2INVENTORS JAMES E. BROML Y WILLIAM H. HILL 1% m. 'TW

ATTORNEY March 13, 1962 J. E. BROMLEY ETAL 3,024,516

APPARATUS FOR TREATING FILAMENT YARN Filed May 18, 1959 v 3 Sheets-Sheet3 INVENTORS JAMES EBROMLEY W/LL/AM H HILLS ,J mfwir ATT RNEY UnitedStates Patent Oflice 3,024,516 Patented Mar. 13, 1962 3,924,516APPARATIE FOR TREATING FILAMENT YARN James E. Bromley and William H.Hills, Pensacola, Fla., assignors to The Chemstrand Corporation,Decatur, Ala., a corporation of Delaware Filed May 18, 1959, Ser. No.813,902 19 Claims. (Cl. 281) This invention relates to a method andapparatus for processing cold-drawable textile filaments formed from athermoplastic polymer. More particularly, this invention relates to amethod and apparatus for continuously stretching and continuouslydeforming substantially parallel synthetic continuous textile filamentsof the nylon type, whereby such filaments are rendered potentiallycrimpable.

Continuous synthetic cold-drawable filaments can be formed from nylonpolymers and the like by the wet, dry, or melt spinning processes, thelast mentioned process being employed in the commercial production ofmost, if not all, of the nylon filaments made today. The freshly formednylon filaments generally are not highly oriented and have relativelylow tensile strength as compared to highly oriented nylon filaments inwhich the molecules are aligned or oriented in the direction of thefilament axis. To orient nylon filaments and thereby to increase greatlythe strength thereof, they may be stretched to .a desired extent byattenuating them by means of thread advancing devices such as two godetsor two other thread advancing means operated at a predeterminedperipheral speed differential therebetween. In the colddrawing ofcontinuous filaments of nylon it is known that stretching isaccomplished advantageously when the point at which stretching occurs isfixed or localized by mechanical or thermal means. The localization ofthe stretch point is carried out ordinarily with the employment of ayarn braking device or the like located between two stretching rolldevices.

Unlike wool, synthetic filaments are relatively straight and have asmooth, slick surface, thereby not being particularly adapted forspinning into spun yarn by the conventional spinning systems. Tofacilitate the carding and/or combing and drafting operations to. whichsynthetic staple fibers are subjected in connection with spinning theminto spun yarn, it is essential to crimp them so that they will have asatisfactory contour or pattern to permit spinning thereof into spunyarn by means of conventional textile processing equipment. Numerousdevices and processes have been proposed to impart this desired crimp orcrinkle to synthetic continuous filaments. One known form of a crimpingdevice uses toothed gearing or serrated engaging wheels that are heatedand adapted to receive the straight continuous filaments and to shapesame by compressive forces into a crimped configuration.

While continuous filament yarns have the advantage of greater evennessand superior strength, they have several undesirable propertiesincluding low heat insulating values, lack of bulkiness desired for someend uses, and low covering power. Many attempts have been made in thepast to impart some of these desirable properties of spun yarn tocontinuous filament yarn. In addition to the fact that the expense ofmanufacturing the yarn is increased considerably, there areunfortunately certain well recognized disadvantages associated with theprior devices and methods for imparting bulk to continuous filamentyarn.

An object of this invention therefore is to provide a simple, rapid, andeconomical method for commercially producing a thermoplastic continuousmultifilarnent or monofilament yarn having a fiuify, stretchablecharacter and possessing many properties associated with spun yarn whileretaining many properties associated with filament yarn such as strengthand freedom from pilling. Another object of this invention is to providea continuous method for drawing and deforming nylon filaments in asingle operation so as to render same potentially highly crimpable.Still another object of this invention is to provide a method forsimultaneously deforming and cooling nylon filaments immediately aftersaid filaments are oriented by a drawing operation. A further object ofthis invention is to provide a method for producing oriented nylonfilaments having potential crimpability. A still further object of thisinvention is to provide an improved stretching and deforming apparatusfor processing nylon or the like. A yet further object of this inventionis to provide an apparatus for processing cold-drawable syntheticfilaments with which unstretched or unoriented continuous filaments arefed by a power driven feed roller through a heat-stretch zone whereinthe filaments are heated and stretched and from which the filaments arefed between positively driven intermeshing toothed wheel members, theteeth of which are in closely spaced adjustment, and a desired number oftimes around one of said members in such a manner to provide reducedtensioning with each Wrap and a separator bar or roller in spacedrelationship therewith and axially askew with respect to the axes ofsaid members.

Other objects and advantages of the present invention will becomeapparent from a study of the following specification, claims, .anddrawing. Preferred embodiments of the apparatus of this invention willnow be described with reference to the accompanying drawing wherein:

FIGURE 1 is a schematic view in perspective with principal parts inlocation illustrating one arrangement of apparatus suitable forpreparing the potentially crimpable thermoplastic filaments of thisinvention;

FIGURE 2 is a fragmental view on a larger scale in perspective partly inaxial section illustrating with more particularity the yarn heatingdevice of the apparatus herein disclosed;

FIGURE 3 is a detailed fragmental plan view illustrating an organizationof two tapered crimping toothed wheel members and a fixed spacer bar, aswell as two externally contacting spur gears operatively associated withsaid members to drive same;

FIGURE 4 is an elevation-a1 view in section illustrating the teeth ofthe wheel members in closely spaced engagement and the teeth of the spurgears in working contact; and

FIGURE 5 is a schematic view in front elevation with principal parts inlocation illustrating another arrangement of apparatus of the presentinvention with which the stretched and deformed filaments can besubjected to an additional heat treatment while relaxed to develop thepotential crimpability therein.

In these various figures the same reference numerals designate likeparts.

In accordance with this invention there is provided an improvedstretching and deforming machine for processing nylon or like syntheticcontinuous filament yarn, the machine being constructed for highlyeflicient and economical operation. This is made possible by the novelconstruction and arrangement of a feed roll assembly and a set ofdrawing and deforming toothed wheel members, together with means forheating the yarn such as a heated draw or stretch pin, a heated plate, aheated tube, and the like interposed between the said roll assembly andsaid members. From a suitable source the yarn is fed to the said feedroll assembly after being passed around or through a suitable tensioningdevice. At least one of the rolls is positively driven. The objectivesof the roll assembly are the provision of a supply of yarn at apredetermined rate and the provision that the yarn will not sliptherethrough or therearound due to the stretch tension subsequentlyapplied. In the yarn path forward with respect to the roll assembly andthe heating means there are disposed a pair of toothed wheel membersdriven in unison and intermeshing in close relationship without comingin contact with each other. At least one of said members is positivelydriven at a predetermined increased speed relative to the delivery speedof the roll assembly such that a stretch is imparted to the yarn betweenthe said roll assembly and said members. The yarn normally advancing inthe heat-stretch zone defined by the roll assembly and the members andin which the yarn heating means is disposed ordinarily contacts thesurface of said heating means to heat the yarn as desired withstretching of the filaments occurring continuously between the rollassembly and the members, including when the filaments are in contactwith the yarn heating means where most of the attenuation of thefilaments is localized. The yarn is directed in operation between saidmembers and preferably around part of the periphery of one of themembers and thence around part of the periphery of a spaced apart rolleror separator bar for a desired number of times with the yarn taking apath that is progressively longitudinally forward with respect to thepoint where said yarn initially is passed between the toothed wheelmembers. By proper spacing of the roller or separator relative to thewheel members, the yarn is intermittently engaged and disengaged betweenthe members either in a random or definite pattern. The members not onlyserve to deform the filaments of the yarn but also function to coolrapidly or to quench and thereby to harden them as they passtherebetween. Hence, the members are made preferably of heat conductivematerial. After being stretched and deformed in such manner, the yarn istaken up by suitable means in an orderly form. In accordance with anadded feature of this invention the yarn after being stretched anddeformed by the toothed wheel members but before collection thereof issubjected to an elevated temperature while under little or no tension todevelop substantially the potential or latent crimp formed therein bythe preceding treatment. In such an arrangement nylon yarn may bestretched at a draw ratio between 1.0 to 1.1 and 1.0 to 6.0 and deformedin accordance with the present invention without ditficulty at filamentthrough-put speeds up to and above 1000 yards per minute.

In the continuous fiilament yarn treating apparatus shown schematicallyin FIGURE 1 to which reference is made now in particular thethermoplastic cold-drawable yarn indicated by numeral 10, such as nylonand the like and composed of a bundle of smooth substantially parallelfilaments that have not been fully oriented is supplied from a yarnsource. Since the yarn is not completely oriented, it is necessary toextend the yarn to be processed in order to obtain the optimum degree ofmolecular orientation therein. The yarn source can be, for example, yarnpackage 11 previously doffed from a conventional spinning machine. Whilethe invention will be described primarily in connection with anapparatus which employs a yarn package so-doffed, it is to be borne inmind that this is merely for the purpose of convenient illustration andin no sense of limitation since apparatus in accordance with the presentinvention likewise may be employed readily for processing continuousyarn which has not been doffed previously from a spinning machine.

In operation, as shown, yarn 10 is passed over and around one end ofbobbin 12 or other yarn holder, such as a pirn or cone holding a yarnsource. The yarn 10 is threaded conventionally around snubbing bar 13which functions as a simple, uncomplex tensioning device to assist inmaintaining an orderly and uniform supply of yarn. It will be perceivedreadily that other tensioning devices such as the gate type can be usedinstead of the tensioning device shown or that the need of a tensioningdevice may be eliminated entirely. From the tensioning device or bar 13the yarn 10 is passed through a yarn guide 14, if needed, and then to arotatably arranged thread advancing means 15 that withdraws the yarnfrom bobbin 12 and supplies same at a controlled supply rate and that isoperated at a first delivery speed. As shown, means 15 comprises a pairof suitably mounted feed rolls, at least one of which is positivelydriven. The rolls have parallel axes and engage each other in operationto nip sufficiently the yarn passing therethrough so that slippage orfree-flight of the yarn between the rolls is prevented.

From thread advancing means 15 the yarn 10 is led downwardly and aroundheated stretch or draw pin 16 where the majority of the attenuation ofthe yarn occurs. The pin is mounted to be stationary and axially askewwith respect to the axes of the feed rolls and has a smooth yarn contactsurface, details of the pin being shown with more particularity inFIGURE 2. After being passed around pin 16 a desired number of times,the yarn 10 is directed downwardly between rotatably mounted and axiallyparallel wheel members 17 and 18 having a plurality of uniformlycircumferentially spaced and longitudinally extending teeth 20 that meshin closely spaced adjustment, said members being spaced a short distancebelow pin 16. Members 17 and 18 are keyed to shafts 21 and 22respectively or are integral therewith. To drive said wheel members inunison there are provided externally contacting spur gears 23 and 24having horizontally parallel axes, that mesh and are fixedly mounted onshafts 21 and 22. As the teeth 20 mesh, the yarn is subjected tolaterally applied strains increasing and decreasing in intensity as theyarn approaches and leaves the horizontal plane in which the axes ofsaid wheel members lie and where said teeth engage the notches definedby said teeth to the greatest extent. After being directed around partof the periphery of one of the members, the yarn is directedtangentially therefrom and then around part of the periphery of a roller25 mounted on a supporting frame for free rotation and positionedadjacent roll 17. A spacer bar fixedly mounted to a frame may be asuitably equivalent spacing means for roller 25. The yarn 10 is woundaround member 17 and roller or spacing means 25 a plurality of times asshown in FIGURE 1. The axis of said roller 25 is positioned at aslightly inclined angle with respect to the axes of members 17 and 18 soas to insure proper longitudinal distribution on and advancement alongthe peripheries of member 17 and roller 25, thus preventingsuperposition of the wraps thereon. In other words, the yarn wrappedaround said members and the horizontally spaced roller associatedtherewith assumes generally the shape of a flattened helix, theconvolutions of which are spaced apart, whereby the yarn advances alongwheel member 17 from the inboard end thereof to the outboard end thereofduring rotation of the members 17 and 18.

By correct positioning of the spacing means 25 with relation to thetoothed wheel members 17 and 18, the moving yarn is periodically engagedand disengaged between the wheels either in a random or definitepattern. Where there is random reengagement, the segments of thefilaments forming the ridges of the corrugations induced during initialdeformation do not form ordinarily the same part of the corrugationspreviously formed, whereby the distortion and deformation occurringduring the operation fortuitously are induced. It is seen further thatthe temperature at which the yarn is directed between the wheel membersprogressively diminishes as the yarn moves longitudinally forward onwheel members 17. Stated another way, where the yarn is passed aplurality of times between the toothed wheel members 17 and 18, thetemperature at which the first deformation is conducted is more elevatedthan during subsequent reengagements of the yarn between the saidwheels. Next, the yarn after forming the outer convolution is fedvertical- 1y downwardly through yarn pigtail guide 26 or the like, ifneeded, which is suitably mounted and located below said wheel members.

The yarn is then taken up in an orderly arrangement in a conventionalmanner by a suitable form of package building apparatus. As shown inFIGURE 1, the yarn is taken up by a ring twisting assembly generallydenoted by reference number 27 which comprises a bobbin 28 adapted to berotated by driven belt 30 in a conventional manner to collect a supplyof the yarn indicated by numeral 31. The assembly further comprises aconventional vertically recriprocatable spinning ring 3-2 carrying aring traveller 33 adapted to revolve freely about the bobbin 28 as theyarn is twisted a desired amount and wound on the bobbin.

It may be desirable in accordance with an important feature of thisinvention to provide a uniform taper or bevel to at least one of thetoothed wheel members, as illustrated, while maintaining the axiallyparallel relationship thereof for more even operation and, among otherthings, to assist in preventing possible jamming of the wheels due tobreakage of the yarn 1t). Hence, when yarn breakage occurs, the yarnwill tend to move outboard along said wheel instead of perhaps becomingaccumulated and entangled thereon. Where the wheel members 17 and 18 aretapered and the yarn progresses longitudinally along these members inthe converging direction, the extent to which the yarn is deformed intoa corrugated shape as it passes between the members from the normallyunbent shape will diminish with the frequency of the corrugationsremaining the same. Hence, it will be observed that as a result ofemploying tapered wheel members, the yarn is subjected to a reducedtension between each successive engagement of the yarn and the wheelmembers. When tapered, the wheel members have the shape of a truncatedcone instead of being cylindrical. It should be understood that thereduced tensioning may be attained by other means.

Reference is made now to FEGURE 2 where one form of a yarn breakingdevice or stretch pin 16 which is called sometimes a snubbing pin isshown in more detail and which is employed according to the presentinvention, said pin being non-rotatably mounted, preferably in theposition indicated in FIGURE 1. The cross-section of the pin for bestresults is preferably circular but also may be elliptical or have anyother suitable cross-sectional design. Since the yarn 10 frictionallyengages the surface of the pin as it travels therearound, the surface ofyarn contact area thereof for best results is smooth or moderatelysmooth and is made of a mechanically very resistant-to-wear material.The stretch pin 16 can be made of a wide variety of wear resistantmaterials i11- cluding stainless steel, chromium plated steel, aluminum,a bonded ceramic and the like. Preferably, it is made of aluminumflame-plated with aluminum oxide or flameplated with sintered tungstencarbide which is extremely resistant to wear and performs efiiciently atthe temperatures employed. The stretch pin 16 is provided with heatingmeans 35 so that the yarn passed therearound is heated to apredetermined elevated temperature. The heating of the pin can beachieved in a suitable manner, e.g., by heated fluid inside thereof orby internal electric resistant heating which is preferred in view of itsconvenience in operation. It is also contemplated within the purview ofthe invention to provide a stretch pin with a high frequency heatingmeans. As shown in FIG- URE 2, stretch pin 16 is provided with anelectrically energizable heater element 35, electrical power beingsupplied thereto through conductive lines 36 having a terminal plug 37adapted for reception in a power outlet source. The heater element maybe embedded in the pin as shown or it may be part of a removablecartridge or insert. While there seems to be no theoretical limit forthe diameter of pin 16, it is desirable to stay within a reasonablerange from a practical standpoint.

Reference is now made to FIGURE 3 where there is shown a frame 38 ormounting Wall being adapted for suitable journalling of shafts 21 and 22therein. In the frame are bearings 46 for supporting shafts 21 and 22and for permitting free rotation thereof, the rings 41 of which areadapted to register with said frame to prescribe the axial movement ofsaid shafts. Members 17 and 18, together with a pair of externallycontacting spur gears 23 and 24, are mounted on shafts 21 and 22, saidmembers being keyed fixedly thereto at 42. and 43'. At least one of saidshafts is driven positively by a suitable drive mechanism, such as by anelectric motor 44- (as shown), gearing, belts, and the like.

As can be seen in FIGURE 4, gears 23 and 24 contact during operation,but teeth 20 extending longitudinally of wheel members 17 and 18 are inclose but spaced adjustment. To be effective for the purpose of theinvention, the lateral pressure applied to the yarn 10 passing betweenmembers 17 and 18 to deform same into a corrugated shape is appliedmostly along the apices of teeth 20 and not in the grooves therebetween.This is accomplished by proper selection of the height and slope of theteeth. The amplitude of the corrugations formed in the yarn iscontrolled as a function of the height of the teeth 20, as well as theextent to which the teeth engage in the grooves. The frequency of thecorrugations, that is the number of alternate ridges and grooves formedin a given length of yarn, is of course controlled as a function of thenumber of teeth disposed along a given segment of the circumference ofthe wheel members 17 and 18.

With reference now to FIGURE 5 where one complete yarn treatinginstallation is shown, including means for developing the potential orlatent crimpability in the yarn, thermoplastic continuous filament yarn10 which is not fully oriented is withdrawn from a yarn package 11 andis passed over one end of bobbin 12 or other yarn holder. The yarn ispassed around snubbing bar 13 and through a pigtail guide 14, afterwhich it is led through a rotatably mounted feed roll assemblydesignated generally by numeral 45, said assembly comprising idler roll46 having a rubber cot and idler roll 47 associated with driven roll 48.Shaft St is attached at an end of roll 46 and is mounted at the otherend at point 51 for pivotal movement of roll 46 about 51. Coiled spring52 is fixed at one end with the other end being attached to shaft 50 asindicated so as to bias swingable idler 46 into frictional engagementwith roll 48. The yarn is passed helically around driven feedroll 48 andidler r011 47 and then contacts heater plate 49, the surface of which isstationary and maintained at a suitable temperature by internalelectrically energizable means. The number of laps of the yarn aroundthese rolls is sufiicient to prevent slippage of the yarn through theroll assembly 45. The yarn then is passed through the toothed wheelmembers 17 and 18 which are rotated normally at a greater peripheralspeed than the peripheral speed of the driving roll 48, therebytensioning and stretching the yarn between said feed roll assembly andsaid members. The drawn yarn is passed helically about wheel 17 andseparator roll 25.

In accordance with an embodiment of the present invention, the drawn,deformed thermoplastic filament yarn is subjected to a final heattreatment in a hot aqueous medium such as steam or by dry heat orcombination of both in a relaxed or substantially relaxed condition.This operation as mentioned above develops the potential crimpabilityinduced in the yarn by the prior operation and simultaneously sets thethus-developed crimp, thereby imparting enhanced bulkiness, crimpiness,and stretchability to the yarn. As shown, the yarn is permitted to fallonto a conveying means 53, as for example an endless driven belt. Formore eflicient operation, the yarn may be layed onto such a belt in azig-zag pattern by means of a traverse piddler (not shown). 'Belt 53carrying the yarn is passed through a heating zone in cabinet 54 havinga radiant heat applicator means 55, such as an array of heating lamps,thus developing the crimpiness in the yarn. It is to be understood, ofcourse, that other apparatus arrangements can be employed for subjectingthe yarn to an elevated temperature while under little or no tension.Without being excessively tensioned the yarn is cooled. This may beaccomplished by passing the yarn without undesirable tensioning for ashort distance through the air, excessive tension being avoided becausethe developed crimpiness may be destroyed thereby. Thereafter, the yarnis taken up in an orderly manner. As illustrated, traverse guide 56 laysthe treated yarn on a bobbin 57 surface driven by roller 58 to form ayarn package 60. It will be appreciated that the speed of yarn take-upon bobbin 57 will be coordinated properly with the delivery speed of theyarn on means 53 so that undue tensioning therebetween an excessive yarnaccumulation on means 53 are prevented.

In accordance with this invention, it has been discovered that filamentyarn of a thermoplastic polymer which is not fully oriented can beadvantageously treated to render same potentially crimpable, and capableof being easily transformed in a yarn having increased elasticity orstretchability and improved bulkiness, this being accomplished in auseful, rapid, and economical method. More particularly, the method ofthis invention comprises providing a source of not fully orientedcontinuous filament yarn in the form of a monofilament or bundle offilaments having little or no twist, the filaments being nylon or thelike. The yarn is continuously passed through a stretching zone whereinthe filaments are heated to an elevated temperature, such as by passingsame around a heated stretch pin or heated plate interposed in saidzone. Immediately after leaving the stretching zone, the filaments aredeformed into a corrugated shape having alternate ridges and grooveswhile being cooled by passing between the engagements of toothed wheels,the teeth of which are fitted together in closely spaced adjustment. Thefilaments are redeformed intermittently into a corrugated shape a numberof times by being passed between said wheels a corresponding number oftimes, each subsequent deformation occurring at a somewhat lowertemperature. Where tapered wheels are employed, the tension to which theyarn is subjected between each successive engagement of the yarn and thewheels is decreased. The yarn which is markedly potentially crimpablethereafter is collected. An additional operation whereby the crimp isdeveloped includes subjecting the yarn while relaxed to another heattreatment as above described.

The method of the present invention is applicable to a wide variety ofcontinuous filament yarns, the requirementment being that the yarn ismade from a thermoplastic fiber-forming resin and which can be extendedby drawing and then show increased molecular orientation along thefilament axis. The yarns may be formed by known techniques from theseresins, including melt extrusion, wet spinning processes, and dryspinning processes. As examples of fiber-forming synthetic polymerswhich are included in the thermoplastic fiber-forming resins may bementioned polyethylene; polypropylene; polyurethane; copolymers of vinylacetate and vinyl chloride; the copolymers of vinylidene chloride and aminor proportion of mono-olefinic compounds copolymerizable therewith,such as, for example, vinyl chloride; homopolymers of acrylonitrile,copolymers of acrylonitrile and a minor proportion of at least onemono-olefinic compound copolymerizable therewith and polymer blendscontaining combined acrylonitrile in a major proportion; copolymers ofvinyl chloride and acrylonitrile; linear polyesters of aromaticd-icarboxylic acids and dihydric compounds, such as polyethyleneterephthalate and the polyester derived from terephthalic acid andbis-1,4-(hydroxymethyl) cyclohexane; linear polycarbonamides such as,for example, polyhexamethylene adipamide, polyhexamethylene sebacamide,polymeric monoaminomonocarboxylic acids, such as polymeric 6-aminocaproic acid; and other'fiber-forming thermoplastic polymers. Mixturesof such fiber-forming synthetic polymers also can be used. The processof this invention is applicable particularly for the treatment of yarngenerally referred to as nylon, including nylon 66, nylon 4, nylon 6,nylon 610, nylon 11, and their fiber-forming copolymers thereof, e.g.,6/66, 6/610/66, 66/610, etc.

While the present process is suitable for treatment of yarn whosefilaments have a normal cross-section such as that produced where aspinneret having circular shaped orifices is employed during themanufacture thereof, unusual effects may be obtained by processing yarnshaving a non-circular cross-section or having an axial passage inaccordance with the present invention. For example, when yarn composedof a plurality of continuous filaments having a body section and aplurality of finned sections or legs integrally joined to said body andradially disposed upon the surface of and extending longitudinally ofthe body, such as yarn of X- or Y-shaped cross-section, is subjected tothe treatment in accordance with the instant invention, the resultingyarn has increased covering power, resiliency, and a crisp feel. Thenumber of fin may be two, three, four, or more; and yarns having thefins are prepared by conventional methods, such as by employing duringspinning a spinneret adapted to produce filaments having the desirednumber of fins or legs. It has been found that the yarn having thenon-circular cross-section and whose bulk has been enhanced by themethod and apparatus of the present invention is excellent for rugs andthe like.

Twisted yarn can be processed as well as untwisted yarn, the requirementbeing that the yarn is not fully oriented. However, it is preferred tostart with a source of yarn having zero twist or substantially no twist.Pretwisting of the yarn is generally unnecessary and for economicconsideration is preferably avoided. The denier of the thermoplasticyarn can vary considerably, as well as the denier of the individualfilaments, the ordinary deniers of commercially available yarn beingcompletely suitable. Yarns having different compositions and deniers canbe combined before being processed to produce novelty effects.

The temperature at which the yarn heating means is operated depends uponmany factors including the type of yarn, the yarn linear speed, and theconstruction thereof. The temperature of the yarn should be elevatedpreferably to a temperature below the temperature at which adjacentfilaments will stick during the process. However, the temperature shouldbe sufficient so that the yarn will be deformed or distorted by theintermeshing of the teeth of the stretching wheels without unduefilament breakage. The temperature to which the yarn is subjected may bein the range of 150 C. to 250 C. when nylon 66 is processed. The surfacetemperature of the yarn heating means will depend on the many factors,such as the denier of the yarn and the speed of the yarn.

By employing the above-described apparatus and process, one produces apotentially or latently crimpable yarn which can be changed easily intoa bulked, highly crimped, stretchable continuous filament yarn. Bulkrefers to the relative volume occupied by a given weight of yarn. Hence,yarn having increased bulk, such as that produced in accordance with thepresent invention, has greater covering power and warmth. Crimped refersto the fact that the filaments contain many crimps, crinkles, curls, andthe like which bend in and out in a sinuous pattern along the length ofthe filaments and which may be in one or more planes. stretchable refersto the fact that the yarns produced in accordance with this inventionare elastic and have the ability to accept a slight longitudinallyapplied stress and thereby to become easily extended a considerablelength without permanent elongation thereof. For example, the yarn canbe elongated 10 to percent or more from its untensioned or relaxedlength and immediately recover from this elongation in the nature of theso-called stretchyarns. It is preferred for some end uses to develop thepotential crimpability of the yarn after same has been converted into atextile article. For instance, the stretched and deformed yarn prior tothe final heat treatment advantageously may be tufted into a carpetafter which the heat treatment is applied. The tufts of yarn disposed onthe face of the carpet will bulk to a notable extent, thereby impartingmore luxurious appearance to the carpet. In such a manner the potentialcrimpability in the yarn which is on the back of the carpet and in thebacking material, since it is tightly held at these points, will not bedeveloped, therebty providing an overall more economical utilization ofthe yarn. It will be noted also that the tufting operation is made moreconvenient when the crimp is subsequently developed.

The following is an example of the above-described method of treatingyarns and filaments of this invention.

Example The filaments used as a yarn source were prepared by meltspinning polyhexarnethylene adiparnide, the crosssection of which wasY-shaped. A yarn composed of 68 of these undrawn filaments, each ofwhich had a denier of 60 and a twist of zero turns per inch, was wound(from a spinning machine) onto a bobbin for treatment.

Apparatus corresponding to that in FIGURE 1 was used to treat the yarn.The yarn was unwound for treatment from the bobbin by passing samethrough a pair of positively driven feed rolls, the rate of withdrawalbeing about 100 yards per minute. From the feed rolls the yarn was ledonto and around a stationary stretch pin one time, the yarn movementdescribing a helical path therearound. The surface temperature of thepin was maintained at 210 C. by an electric resistant heater locatedinside the pin and controlled by a thermistor temperature sensingcontrol device. The yarn was fed between two metal toothed wheelsmeshing but not having contacting teeth. The wheels were driven inunison at a predetermined speed so that a stretch of about 400 percentoccurred in the yarn between the feed rolls and withdrawal from thewheels. The yarn was passed through the wheels for an additional threetimes; before each pass the yarn was directed around a spaced roller.Thereupon the yarn was collected on a conventional ring twisterassembly.

A tufted carpet was produced from the yarn so treated. The carpet wassubjected to live steam at an elevated temperature of 130 'C., therebydeveloping the potential crimpability therein. The resulting carpet hada fluffy, bulky appearance and possessed an esthetic appeal.

From the foregoing it is seen that the advantages of the presentinvention are many. The methods result in the production of yarns havingdesirable bulk and are broadly applicable to produce such yarns from awide range of cold-drawable filaments manufactured from thermoplasticresins. The improved device for processing continuous filaments, forexample, of the nylon type, which may be run at a high speed and highefiiciency requires little operator attention. The construction andarrangement of the device make it possible to convert at moderateexpense existing textile processing equipment such as a draw twisteradapted for nylon processing into a machine of the type disclosed andclaimed herein. By relatively simple adjustment the apparatus of thepresent invention can be adapted easily for the production of yarnhaving a low crimpability to a high crimpability. The inherentproperties of the treated yarn are such that they impart numerous anddesirable properties in woven, non-woven, and knitted fabrics. Yarnscomposed of non-circular cross-sections and processed in accordance withthe present invention have increased resiliency and enhanced coveringpower eminently suitable for rugs, carpets, and the like.

The term yarn is used herein in the specification, in the description ofthe invention, and in the claims as referring to continuousmultifilaments, as well as to a continuous monofilament. Many differentembodiments of the invention may be made without departing from thespirit and scope thereof. For example, while one yarn treating unit isillustrated in the annexed drawing, it will be appreciated readily thatthe apparatus of the instant invention may be provided with a pluralityof identical yarn processing units along its length or having two banksof such points in back to back relationship. Moreover, novelty effectsof various sorts may be imparted to the yarn by irregular or regularvariations in the yarn speeds and stretches. Furthermore, it will beappreciated that an undrawn thermoplastic yarn may be treated togetherwith a drawn yarn or with a yarn which is not thermoplastic such asregenerated cellulose yarn. Therefore, it is to be understood that theinvention is not to be limited to the specific embodiments shown anddescribed herein, except as defined in the appended claims.

What is claimed is:

1. An apparatus for treating a synthetic continuous filament yarn madefrom a nylon polymer whereby potential crimpiness is imparted theretocomprising, in combination, rotatably mounted thread advancing rollsadapted to supply a molecularly orientable nylon continuous filamentyarn from a source at a predetermined first rate, a pair of toothedwheel members having horizontally disposed parallel axes, each memberbeing fixedly mounted on separate shafts journaled in a supportingframe, the teeth of said wheel members being uniformly circumferentiallyarranged to be engageable therebetween in closely spaced adjustment andextending in parallel relation along the lengths of said members, saidmembers being adapted to receive said yarn and to advance same at apredetermined increased rate as compared to the supply rate of saidyarn, whereby the yarn normally advancing between said thread advancingrolls and said wheel members is attenuated a predetermined extentthereby to increase the molecular orientation thereof means to drivesaid pair of wheel members in unison, a non-rotatable stretch pinmounted at one of its ends in the filament path between said threadadvancing rolls and said wheel members and having a smooth wearresistant filament contact surface around which said yarn is wrapped inoperation at least once and describes a helical path extendinglongitudinally forward with respect to the mounted end of said pin,electrically energizable resistant heater inside said pin to heat sameinternally, thereby to localize the attenuation of said yarn and toimpart heat to said yarn in its travel between said thread advancingrolls and said wheel members, a separator roll mounted adjacent saidwheel members in spaced relationship therewith and positioned at aslight angle with respect to the axes of said wheel members in orderthat the yarn normally progressing around one wheel member and saidseparator roll will describe generally a helix, the convolutions ofwhich are spaced apart, whereby the yarn advances along the one wheelmember from the inboard end thereof to the outboard end thereof duringrotation of said wheel members, said pair of wheel members beingpositioned adjacent said stretch pin in spaced relation therewith sothat said wheel members are adapted to receive the heated yarn forthwithfrom said stretch pin, and means for taking up said yarn in an orderlymanner after said yarn has passed between said pair of wheel members andaround said separator roll a plurality of times.

2. The apparatus as set forth in claim 1 further characterized in thatat least one of said pair of toothed wheel members has a uniformlytapered surface converging in the direction away from said supportingframe.

3. The apparatus as set forth in claim 1 further characterized in thatsaid thread advancing rolls comprise a pair of rolls having horizontallydisposed parallel axes, at least one of said rolls being positivelydriven.

4. The apparatus as set forth in claim 1 further characterized in thatsaid means for taking up said yarn comprises a ring twisting assembly.

5. The apparatus as set forth in claim 1 further characterized in that apair of external spur gears having parallel axes are fixedly mounted onsaid shafts and adapted for working contact to provide unison rotationof said pair of wheel members and to maintain the closely spacedrelation therebetween.

6. The apparatus as set forth in claim 5 further characterized in thatthe apparatus includes means for imparting rotation to at least one ofsaid shafts.

7. The apparatus as set forth in claim 1 further characterized in thatsaid thread advancing rolls comprise three rolls, one of which ispositively driven with the other two being idler rolls mounted for freerotation, one of said idler rolls being pivotally mounted about a pointand spring biased into rotating engagement with the driven roll.

8. The apparatus as set forth in claim 1 further characterized in thatsaid separator roll is mounted to a frame for free rotation.

9. The apparatus as set forth in claim 1 further characterized in thatsaid separator roll is non-rotatably mounted.

10. An apparatus for treating a synthetic continuous filament yarn madefrom a thermoplastic polymer comprising, in combination, means forsupplying a molecularly orientable synthetic continuous filament yarnmade from a thermoplastic polymer from a source at a first rate, toothedWheel members, the teeth of which are circumferentially disposed thereonand engageable therebetween in closely spaced adjustment, said membersbeing adapted to receive said yarn and to advance same at an increasedrate as compared to the supply rate of said yarn, whereby the yarnnormally advancing between said yarn supply means and said wheel membersis attenuated thereby to increase the molecular orientation thereof,means between said yarn supply means and said wheel members forelevating the temperature of said yarn, thereby to localize theattenuation of said yarn in its travel between said yarn supply meansand said wheel members, means for subjecting said yarn in a relaxedcondition to a heat treatment thereby to develop the potentialcrimpiness induced in the yarn, and means for taking up said yarn in anorderly manner after said heat treatment.

11. An apparatus for treating a continuou filament yarn made from anylon polymer comprising, in combination, rotatably mounted threadadvancing rolls adapted to supply a molecularly orientable nyloncontinuous filament yarn from a source at a predetermined first rate, apair of rotatably mounted toothed wheel members having parallel axes,the teeth of which are circumferentially arranged to be engageabletherebetween in closely spaced adjustment and extending along thelengths of said members, said members being adapted to receive said yarnand to advance same at a predetermined increased rate as compared to thesupply rate of said yarn, whereby the yarn normally advancing betweensaid thread advancing rolls and said wheel members is attenuated apredetermined extent thereby to increase the molecular orientationthereof, means to drive said pair of wheel members in unison, a yarnheating device for heating said yarn to an elevated temperature in thefilament path between said thread advancing rolls and said wheelmembers, electrically energizable means for heating said yarn heatingdevice internally, thereby to localize the attenuation of said yarn andto impart heat to said yarn in its travel between thread advancing rollsand said wheel members, a separator roll mounted adjacent said wheelmembers in spaced relationship therewith and positioned so that its axisis disposed at a slight angle with respect to the axes of said wheelmembers, said pair of wheel members being positioned adjacent said yarnheating device in spaced relation therewith so that said wheel membersare adapted to receive the heated yarn forthwith from said yarn heatingdevice, and means for subjecting said yarn in a relaxed condition to aheat treatment thereby to develop the potential crimpiness induced inthe yarn and to set the thus-developed crimpiness prior to taking upsaid yarn in an orderly manner.

12. The apparatus as set forth in claim 11 further characterized in thatat least one of said pair of toothed wheel members has a uniformlytapered surface.

13. An apparatus for treating a continuous filament yarn made from anylon polymer comprising, in combination, rotatably mounted threadadvancing rolls adapted to supply a molecularly orientable nyloncontinuous filament yarn from a source at a predetermined first rate, apair of toothed Wheel members having horizontally disposed parallelaxes, each member being fixedly mounted on separate shafts journaled ina supporting frame, the teeth of said wheel members beingcircumferentially arranged to be engageable therebetween in closelyspaced adjustment and extending in parallel relation along the lengthsof said members, said members being adapted to receive said yarn and toadvance same at a predetermined increased rate as compared to the supplyrate of said arn, whereby the yarn normally advancing between saidthread advancing rolls and said wheel members is attenuated apredetermined extent thereby to increase the molecular orientationthereof, means to drive said pair of wheel members in unison, anon-rotatable yarn stretch pin mounted at one of its ends in thefilament path between said thread advancing rolls and said wheel membersand having a smooth wear resistant filament contact surface around whichsaid yarn is wrapped in operation and describes a helical path extendinglongitudinally forward with respect to the mounted end of said pin,electrically energizable resistant heater inside said pin to heat sameinternally, thereby to localize the attenuation of said yarn and toimpart heat to said yarn in its travel between said thread advancingrolls and said wheel members, a separator roll mounted adjacent saidwheel members in spaced relationship therewith and positioned at aslight angle with respect to the axes of said Wheel members in orderthat the yarn progressing around one wheel member and said separatorroll will describe generally a helix, the convolutions of which arespaced apart, whereby the yarn advances along the one wheel member fromthe inboard end thereof to the outboard end thereof during rotation ofsaid wheel members, said pair of wheel members being positioned adjacentsaid stretch pin in spaced relation therewith so that said wheel membersare adapted to receive the heated yarn forthwith from said stretch pin,means for conveying said yarn adapted to receive same after said yarnhas passed between said pair of wheel members and around said separatorroll a plurality of times and to move said yarn continuously through aheating zone thereby to develop the potential crimpiness in the yarn andto set the thus-formed crimpiness prior to taking up said yarn in anorderly manner.

14. The apparatus as set forth in claim 13 further characterized in thatat least one of said pair of toothed wheel members has a uniformlytapered surface converging in the direction away from said supportingframe.

15. The apparatus as set forth in claim 13 further characterized in thata pair of external spur gears having parallel axes are fixedly mountedon said shafts and adapted for working contact to provide unisonrotation of said wheel members and to maintain the closely spacedrelation therewith.

16. An apparatus for texturing a synthetic continuous filament yarn madefrom a thermoplastic polymer whereby potential crimpiness is impartedthereto comprising, in combination, a rotatably mounted thread advancingmeans adapted to supply a molecularly orientable synthetic continuousfilament yarn made from a thermoplastic polymer from a source at a firstrate, rotatably mounted toothed wheel members, the teeth of which arecircumferentially arranged to be engageable therebetween in closelyspaced adjustment and extend along the lengths of said members, saidmembers being adapted to receive said yarn and to advance same at anincreased rate as compared to the supply rate of said yarn, whereby theyarn normally advancing between said thread advancing means and saidwheel members is attenuated a predetermined extent thereby to increasethe molecular orientation thereof, and whereby successive portions ofsaid yarn are subjected to forces laterally applied by said teethalternately in one direction and then in the opposite direction to causedeformation of the yarn mostly along the apices of said teeth, a yarnheating device in the yarn path between said advancing means and saidwheel members to heat said yarn by surface contact therewith and tolocalize the attenuation of said yarn between said thread advancingmeans and said wheels members, a separator mounted adjacent to saidWheel members in spaced relation therewith and positioned so that theaxis of the separator is disposed at a slight angle with respect to theaxis of one of the wheel members in order that the yarn normallyprogressing around one wheel member and said separator will describegenerally a helix, the convolutions of which are spaced apart, and meansfor taking up said yarn in an orderly manner after said yarn has passedbetween said wheel members and around said separator a plurality oftimes.

17. An apparatus for texturing a synthetic continuous filament yarn madefrom a thermoplastic polymer whereby potential crimpiness is impartedthereto comprising, in combination, rotatably mounted thread advancingrolls adapted to supply a molecularly orientable synthetic continuousfilament yarn made from a thermoplastic polymer from a source at apredetermined first rate, rotatably mounted toothed wheel members, theteeth of which are uniformly circumferentially arranged to be engageabletherebetween in closely spaced adjustment and extend along the lengthsof said members, said members being adapted to receive said yarn and toadvance same at a predetermined increased rate as compared to the supplyrate of said yarn, whereby the yarn normally advancing between saidthread advancing rolls and said wheel members is attenuated apredetermined extent thereby to increase the molecular orientationthereof and whereby successive portions of said yarn are subjected toforces laterally applied by said teeth alternately in one direction andthen in the opposite direction to cause deformation of the yarn mostlyalong the apices of said teeth, a yarn heating device in the yarn pathbetween said thread advancing rolls and said wheel members to heat saidyarn by surface contact therewith and to localize the attenuation ofsaid yarn in its travel between said thread advancing rolls and saidwheel members, said yarn heating device being provided with internalheating means, a separator roll mounted adjacent to said wheel membersin spaced relation therewith and positioned so that the axis of theseparator roll is disposed at a slight angle with respect to the axis ofone of the wheel members in order that the yarn normally progressingaround one wheel member and said separator roll will describe generallya helix, the convolutions of which are spaced apart, and means fortaking up said yarn in an orderly manner after said yarn has passedbetween said wheel members and around said separator roll a plurality oftimes.

18. An apparatus for treating a synthetic continuous filament yarn madefrom a thermoplastic polymer whereby potential crimpiness is impartedthereto comprising, in combination, rotatably mounted thread advancingrolls adapted to supply a molecularly orientable synthetic continuousfilament yarn made from a thermoplastic polymer from a source at apredetermined first rate, rotatably mounted toothed wheel members, theteeth of which are uniformly circumferentially arranged to be engageabletherebetween in closely spaced adjustment and extend along the lengthsof said members, said members being adapted to receive said yarn and toadvance same at a predetermined increased rate as compared to the supplyrate of said yarn, whereby the yarn normally advancing betweensaidthread advancing rolls and said wheel members is attenuated apredetermined extent thereby to increase the molecular orientationthereof and whereby successive portions of said yarn are subjected toforces laterally applied by said teeth alternately in one direction andthen in the opposite direction to cause deformation of the yarn mostlyalong the apices of said teeth, a non-rotative yarn stretch pin in theyarn path between said thread advancing rolls and said wheel membershaving a smooth wear resistant filament contact surface and around whichsaid yarn is wrapped in operation to localize the attenuation of saidyarn and to impart heat to said yarn in its travel between said threadadvancing rolls and said wheel members, electrically energizable meansfor heating said pin internally, a separator roll mounted adjacent tosaid wheel members in spaced relation therewith and positioned so thatthe axis of the separator roll is disposed at a slight angle withrespect to the axis of one of the wheel members in order that the yarnnormally progressing around one wheel member and said separator rollwill describe generally a helix, the convolutions of which are spacedapart, and means for taking up said yarn in an orderly manner after saidyarn has passed between said wheel members and around said separatorroll a plurality of times.

19. An apparatus for treating a synthetic continuous filament yarn madefrom a nylon polymer whereby potential crimpiness is imparted theretocomprising, in combination, rotatably mounted thread advancing rollsadapted to supply a molecularly orientable nylon continuous filamentyarn from a source at a predetermined first rate and to nip yarntherebetween, a pair of rotatably mounted toothed wheel members havingparallel axes, the teeth of which are uniformly circumferentiallyarranged to be engageable therebetween in closely spaced adjustment andextend along the lengths of said members, said members being adapted toreceive said yarn and to advance same at a predetermined increased rateas compared to the supply rate of said yarn, whereby the yarn normallyadvancing between said thread advancing rolls and said wheel members isattenuated a predetermined extent thereby to increase the molecularorientation thereof and whereby successive portions of said yarn aresubjected to forces laterally applied by said teeth alternately in onedirection and then in the opposite direction to cause deformation of theyarn mostly along the apices of said teeth, means to drive said pair ofwheel members in unison, a yarn heater plate in the yarn path betweensaid thread advancing roll and said Wheel members which said yarncontacts in operation to localize the attenuation of said yarn and toimpart heat to said yarn in its travel between said thread advancingrolls and said wheel members, electrically energizable means for heatingsaid plate internally, a separator roll mounted adjacent to said wheelmembers in spaced relation therewith and positioned so that the axis ofthe separator roll is disposed at a slight angle with respect to theaxes of said wheel members in order that the yarn normally progressingaround one wheel member and said separator roll will describe generallya heliX, the convolutions of which are spaced apart, said pair of wheelmembers being positioned adjacent to said yarn heater plate in spacedrelation therewith so that said wheel members are adapted to receive theheated yarn forthwith from said yarn heater plate, and means for takingup said yarn in an orderly manner after said yarn has passed betweensaid pair of wheel members and around said separator roll a plurality oftimes.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Slayter May 2, 1944 Taylor Oct. 2, 1945 5Keen Feb. 16, 1954 16 Shattuck June 26, 1956 Lawson et a1 Nov. 12, 1957Stewart et a1. Dec. 3, 1957 Eshuis Oct. 14, 1958 Sellers Feb. 24, 1959

1. AN APPARATUS FOR TREATING A SYNTHETIC CONTINUOUS FILAMENT YARN MADEFROM A NYLON POLYMER WHEREBY POTENTIAL CRIMPINESS IS IMPARTED THERETOCOMPRISING, IN COMBINATION, ROTABLY MOUNTED THREAD ADVANCING ROLLSADAPTED TO SUPPLY A MOLECULARLY ORIENTABLE NYLON CONTINUOUS FILAMENTYARN FROM A SOURCE AT A PREDETERMINEDF FIRST RATE, A PAIR OF TOOTHEDWHEEL MEMBERS HAVING HORIZONTALLY DISPOSED PARALLEL AXES, EACH MEMBERBEING FIXEDLY MOUNTED ON SEPARATE SHAFTS JOURNALED IN A SUPPORTINGFRAME, THE TEETH OF SAID WHEEL MEMBERS BEING UNIFORMLY CIRCUMFERENTIALLYARRANGED TO BE ENGAGEABLE THEREBETWEEN IN CLOSELY SPACED ADJUSTMENT ANDEXTENDING IN PARALLEL RELATION ALONG THE LENGTHS OF SAID MEMBERS, SAIDMEMBERS BEING ADAPTED TO RECEIVE SAID YARN AND TO ADVANCE SAME AT APREDETERMINED INCREASED RATE AS COMPARED TO THE SUPPLY RATE OF SAIDYARN, WHEREBY THE YARN NORMALLY ADVANCING BETWEEN SAID THREAD ADVANCINGROLLS AND SAID WHEEL MEMBERS IS ATTENUTATED A PREDETERMINED EXTENTTHEREBY TO INCREASE THE MOLECULAR ORIENTATION THEREOF MEANS TO DRIVESAID PAIR OF WHEEL MEMBERS IN UNISION, A NON-ROTATABLE STRETCH PINMOUNTED AT ONE OF ITS ENDS IN THE FILAMENT PATH BETWEEN SAID THREADADVANCING ROLLS AND SAID WHEEL MEMBERS AND HAVING A SMOOTH WEARRESISTANT FILAMENT CONTACT SURFACE AROUND WHICH SAID YARN IS WRAPPED INOPERATION AT LEAST ONCE AND DESCRIBES A HELICAL PATH EXTENDINGLONGITUDINALLY FORWARD WITH RESPECT TO THE MOUNTED END OF SAID PIN,ELECTRICALLY ENERGIZABLE RESISTANT HEATER INSIDE SAID PIN TO HEAT SAMEINTERNALLY, THEREBY TO LOCALIZE THE ATTENTUATION OF SAID YARN AND TOIMPART HEAT TO SADI YARN IN ITS TRAVEL BETWEEN SAID THREAD ADVANCINGROLLS AND SAID WHEEL MEMBERS, A SEPARATOR ROLL MOUNTED ADJACENT SAIDWHEEL MEMBERS IN SPACED RELATIONSHIP THEREWITH AND POSITIONED AT ASLIGHT ANGLE WITH RESPECTT TO THE AXES OF SAID WHEEL MEMBERS IN ORDERTHAT THE YARN NORMALLY PROGRESSING AROUND ONE WHEEL MEMBER AND SAIDSEPARATOR ROLL WILL DESCRIBE ENERALLY A HELIX, THE CONVOLUTIONS OF WHICHARE SPACED APART, WHEREBY THE YARN ADVANCES ALONG THE ONE WHEEL MEMBERFROM THE INBOARD END THEREOF TO THE OUTBOARD END THEREOF DURING ROTATIONOF SAID WHEEL MEMBERS, SAID PAIR OF WHEEL MEMBERS BEING POSITIONEDADJACENT SAID STRETCH PIN IN SPACED RELATION THEREWITH SO THAT SAIDWHEEL MEMBERS ATE ADAPTED TO RECEIVE THE HEATED YARN FORTHWITH FROM SAIDSTRETCH PIN, AND MEANS FOR TAKING UP SAID YARN IN AN ORDERLY MANNERAFTER SAID YARN HAS PASSED BETWEEN SAID PAIR OF WHEEL MEMBERS AND AROUNDSAID SEPARATOR ROLL A PLURALITY OF TIMES.